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        <h5 class="mb-0 mx-auto">答案解析</h5>
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            <h6>题目：</h6>
            <p>已知函数f(x)=ln(x+√(x²+1))，则f'(x)=?</p>
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        <div class="correct-answer mb-3">
            正确答案：A. 1/√(x²+1)
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            <h6>解题步骤：</h6>
            
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                <span class="step-number">Step 1:</span>
                <p>利用复合函数求导法则，设u=x+√(x²+1)，则f(x)=ln(u)</p>
                <div class="formula">
                    f'(x) = 1/u · u'
                </div>
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                <span class="step-number">Step 2:</span>
                <p>求u'，注意√(x²+1)的求导</p>
                <div class="formula">
                    u' = 1 + (2x)/(2√(x²+1)) = 1 + x/√(x²+1)
                </div>
            </div>

            <div class="step-item">
                <span class="step-number">Step 3:</span>
                <p>代入公式</p>
                <div class="formula">
                    f'(x) = [1 + x/√(x²+1)] / [x + √(x²+1)]
                </div>
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                <span class="step-number">Step 4:</span>
                <p>化简</p>
                <div class="formula">
                    = 1/√(x²+1)
                </div>
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            <h6>考点分析：</h6>
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                <span class="knowledge-tag">复合函数求导</span>
                <span class="knowledge-tag">根式求导</span>
                <span class="knowledge-tag">分式化简</span>
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                <p><strong>易错点：</strong></p>
                <ul>
                    <li>根式求导时容易忘记链式法则</li>
                    <li>最后一步化简计算较复杂，需要注意代数技巧</li>
                </ul>
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